Peppermint(Mentha piperita): Peppermint has been a popular folk remedy for digestive disorders for over two hundred years and is currently one of the most economically significant aromatic food/medicine crops produced in the United States.⁷⁸

In some countries in Europe, peppermint leaf is recognized as a digestive aid due to the carminative (gas-preventing) and cholagogue (bile increasing) action of the aromatic oil. In Germany, peppermint oil is approved as an over-the-counter drug for upper gastrointestinal cramps and spastic conditions of bile ducts, catarrh (inflammation of mucous membranes) of upper respiratory area, and inflammation of oral mucosa.⁷⁹ It is also approved (in enteric, coated capsules) for irritable bowel syndrome, as the oil exerts a relaxing effect on the smooth muscles of the bowel. Peppermint oil also has antibacterial properties, as do many essential oils. Peppermint oil and menthol are common ingredients in over-the-counter external analgesic products like balms and liniments. In Germany, this combination is approved for external use for muscle and nerve pain.⁸⁰ In addition to the above conditions, peppermint oil is approved by ESCOP (the European Scientific Cooperative in Phytotherapy) for gallbladder inflammation and gallstones, and skin conditions such as pruritis (severe itching) and urticaria (eruption of wheals with intense itching).